bug 61300 -- prevent really long (infinite?) loop on corrupt file

main/POIFS/FileSystem/NDocumentInputStream.cs

@@ -69,6 +69,10 @@ namespace NPOI.POIFS.FileSystem
             _marked_offset_count = 0;
             _document_size = document.Size;
             _closed = false;
+            if (_document_size < 0)
+            {
+			    // throw new RecordFormatException("document_size cannot be < 0");
+		    }
 
             DocumentProperty property = (DocumentProperty)doc.Property;
             _document = new NPOIFSDocument(
@@ -277,6 +281,10 @@ namespace NPOI.POIFS.FileSystem
 
         public override void ReadFully(byte[] buf, int off, int len)
         {
+            if (len < 0)
+            {
+               throw new RuntimeException("Can't read negative number of bytes");
+            }
             CheckAvaliable(len);
 
             int read = 0;

main/POIFS/FileSystem/ODocumentInputStream.cs

@@ -19,6 +19,7 @@
 using System;
 using NPOI.POIFS.Storage;
 using System.IO;
+using NPOI.Util;
 
 namespace NPOI.POIFS.FileSystem
 {
@@ -71,6 +72,10 @@ namespace NPOI.POIFS.FileSystem
             _current_offset = 0;
             _marked_offset = 0;
             _document_size = document.Size;
+            if (_document_size < 0)
+            {
+			    throw new RecordFormatException("document_size cannot be < 0");
+		    }
             _closed = false;
             _document = documentNode.Document;
             _currentBlock = GetDataInputBlock(0);

main/Util/IOUtils.cs

@@ -373,6 +373,10 @@ namespace NPOI.Util
             int count;
             while ((count = inp.Read(buff, 0, buff.Length)) >0)
             {
+                if (count < -1)
+                {
+                    throw new RecordFormatException("Can't have read < -1 bytes");
+                }
                 out1.Write(buff, 0, count);
             }
         }

testcases/main/HSSF/UserModel/TestBugs.cs

@@ -46,6 +46,7 @@ namespace TestCases.HSSF.UserModel
     using NPOI.HSSF;
     using System.Net;
     using SixLabors.ImageSharp;
+    using NPOI.HPSF;
 
     /**
      * Testcases for bugs entered in bugzilla
@@ -2369,8 +2370,8 @@ namespace TestCases.HSSF.UserModel
             ClassicAssert.AreEqual(3, wb.NumberOfSheets);
 
             // Find the SST record
-            UnicodeString withExt = wb.Workbook.GetSSTString(0);
-            UnicodeString withoutExt = wb.Workbook.GetSSTString(31);
+            NPOI.HSSF.Record.UnicodeString withExt = wb.Workbook.GetSSTString(0);
+            NPOI.HSSF.Record.UnicodeString withoutExt = wb.Workbook.GetSSTString(31);
 
             ClassicAssert.AreEqual("O:Alloc:Qty", withExt.String);
             ClassicAssert.IsTrue((withExt.OptionFlags & 0x0004) == 0x0004);
@@ -3510,6 +3511,19 @@ namespace TestCases.HSSF.UserModel
             wb.Close();
         }
 
+        [Test]
+        public void Test61300()
+        {
+            ClassicAssert.Throws<RuntimeException>(()=>{
+                NPOIFSFileSystem npoifs = new NPOIFSFileSystem(HSSFTestDataSamples.OpenSampleFileStream("61300.xls"));
+
+                DocumentEntry entry =
+                        (DocumentEntry) npoifs.Root.GetEntry(SummaryInformation.DEFAULT_STREAM_NAME);
+                PropertySet properties =
+                        new PropertySet(new DocumentInputStream(entry));
+            });
+        }
+
         // follow https://svn.apache.org/viewvc?view=revision&revision=1896552 to write a unit test for this fix.
         [Test]
         public void Test52447()